Compacting roller for centrifugal casting machine



c. w. CHANLUND ET AL 2,722,044

COMPACTING ROLLER FOR CENTRIFUGAL CASTING MACHINE Nov. 1, 1955 3 Sheets-Sheet 1 Filed April 11, 1952 D RNFNL miw m w m N W2 M H m E w m H n m 0 me m @(5 6W r 2. o M W O m m n u 3 3f w w w L w N w m V 5 5 7 7 G 6 1955 c. w. CHANLUND ETAL 2,722,044

COMPACTING ROLLER FOR 'CENTRIFUGAL CASTING momma Filed April 11, 1952 3 Sheets-Sheet 2 h INVENTOR. r j CHEL w. CHHNLUND 80 a 82 8| 83 BYGEOEGE Ii. JESSE/V /'7 TTOENEYS Nov. 1, 1.955 c. w. CHANLUND ETAL 2,722,044

COMPACTING ROLLER FOR CENTRIFUGAL CASTING MACHINE Filed April 11, 1952 v3 Sheets-Sheet 3 INVENTOR. CH/PL W. CHHNLUND GEORGE /E. JESS-EN f7 T'TOENEYS United States Patent COMPACTING ROLLER FOR CENTRIFUGAL CASTING MACHINE Carl Wilmer Chanlund and George Ronald Jessen, Salt Lake City, Utah, assignors, by mesne assignments, to Cen-Vi-Ro Pipe Corporation, South Gate, Calif., a corporation of Delaware Application April 11, 1952, Serial No. 281,784

4 Claims. (Cl. 25-30) This invention relates to improvements in compacting rollers for use in machines for forming concrete pipes or the like, or for the lining of metal or other pipes with concrete or like material.

One of the principal objects of this invention is to provide a novel form of compacting roller for use in machines for centrifugally casting concrete pipe or the like, or for the lining of metal or other pipes with concrete or like material.

Another object of this invention is to provide a novel compacting roller for use in centrifugal concrete casting machines, which roller is especially adapted to produce a casting having a smooth interior surface.

Another object of this invention is to produce a compacting roller for use in centrifugal concrete casting machines, which roller provides for more uniform distribution of the concrete materials throughout the mass.

A further object of this invention is to provide a novel compacting roller for a centrifugal casting apparatus, which roller is provided with surfaces permitting selective compacting and troweling of the concrete.

Yet another object of this invention is to provide a compacting roller for use in centrifugal casting apparatus, which roller incorporates means for embedding excess coarse aggregate material under the surface of the article being molded or cast.

Other objects and advantages of this invention, it is believed, will be readily apparent from the following detailed description of the preferred embodiments thereof when read in conjunction with the accompanying drawings.

In the drawings:

Figure l is an end view of a machine for making concrete pipe and incorporating the present invention.

Figure 2 is a sectional elevation taken substantially on the line 2-2 of Figure 1.

Figure 3 is a sectional elevation taken substantially on the line 33 of Figure 2.

Figure 4 is a side elevation of one form of compacting roller.

Figure 5 is a vertical sectional view of a portion of the machine, illustrating the compacting roller of Figure 4 in operative position.

Figure 6 is a side elevation of a modified form of compacting roller.

Figure 7 is a sectional elevation taken substantially on the line 77 of Figure 6.

Figure 8 is a side elevation of another modified form of compacting roller.

Figure 9 is a sectional elevation taken substantially on the line 9-9 of Figure 8.

Figure 10 is a side elevation of another modified form of compacting roller.

Figure 11 is a side elevation of yet another modified form of compacting roller.

Figure 12 is a sectional elevation taken substantially on the line 1212 of Figure 11. V

' Referring now to the drawings, in Figures 1 and 2 is ice illustrated a centrifugal concrete pipe casting machine generally indicated 10. This machine is not shown in detail nor is it hereinafter described at length since it forms the subject matter of the copending application of George R. lessen, et al., Serial No. 187,452, filed September 29, 1950, now Patent No. 2,671,260.

Briefly, this machine includes a supporting frame 11 on which is provided a pair of trunnion rollers 12 of pneumatic tire construction and driven by a power source 13 through a'suitable drive shaft 14 and differential or gear box 15. The driven trunnion rollers 12 cooperate with a pair of suitably journaled idler trunnions 16 in supporting and spinning the hollow cylindrical mold 17. A pair of spaced stabilizer trunnion rollers 18 is provided on one side of the machine, each journaled in one of a pair of arms 19 secured to rock shaft 20; and a like pair of rollers 21 is provided on the other side of the machine, each journaled on one of a pair of arms 22 secured to rock shaft 23. Crank arms 24 and 25 are each secured at one end to rock shafts 20 and 23, respectively, and at the other end to piston rods 26 and 27 of suitable power cylinder assemblies (not shown) for operation of the respective rock shafts to move the stabilizer trunnions from the operative position shown in the solid lines of Figure 1 to the inoperative position indicated by the phantom lines thereof.

The mold 17 comprises a pair of spaced shells 30 and 31 separated by means of annular ribs 32. Welded to the shells is a pair of longitudinal flanges 33 and 34, bolts 35 being provided to maintain the mold in its closed or operating position. A pair of annular rows of trunnion guides 36 is employed on the outer shell 30 to prevent lateral displacement of the mold during operation of the machine.

Means are provided for imparting a vibratory motion to the mold 17 to improve the operation of the machine, and as shown in the drawings, these means may include the vibrators 40 which bear against the underside of the mold 17. These vibrators each include an eccentric weight (not shown) attached to a shaft 41 driven through suitable transmission 42 by means of the motor 44. Shaft 41 is journaled at one end of each of a plurality of arms 43, which arms are carried on a rock shaft 45.

Also carried on the shaft 45 is a crank arm 46 to which is pivotally connected the piston rod 47 of a power cylinder assembly 48. It will be thus understood that the position of the vibrators 40 as well as the pressure of the same against the mold 17 may be controlled by actuation of the power cylinder assembly 48.

The compacting roller 50 which comprises a preferred embodiment of this invention extends longitudinally through the mold 17 and is mounted to be freely axially rotatable. As shown, the roller 50 is generally tubular in shape and is journaled at one end on suitable bearings (not shown) on a shaft 51 and at the other end on a stub shaft 52. Means (not shown) are provided for disengagement of the stub shaft 52 from the roller 50 so that the mold 17 may be removed from the machine without disassembly of the roller 50. These means are described in detail in the Jessen application referred to above.

Means are provided for adjusting the position of the compacting roller 50 with respect to the mold 17, and as shown best in Figures 1 and 2, these means may include the arm 55 at one end of the machine and the arm 56 at the other end thereof. The shafts 51 and 52 are carried on the outer ends of the arms 55 and 56, respectively, the other ends of said arms being pivotally connected on the rock shaft 45. Pivotally connected to the outer end of the arm 55 is the piston rod 57 of the power cylinder assembly 58. Through operation of the power cylinder assembly the compacting roller-may be moved from the inoperative position shown in Figure 1 downwardly to the operative. position. wherein. the. roller bears against. the concrete.

The surface of the roller 50 is provided with a plurality of equally spaced longitudinal flutes. or grooves 60:. separated by lands 61. Preferably these. grooves are. formed in two oppositely-disposed: groups, the smooth arcuate surfaces 62 of the roller therehetween. serving as. troweling areas as will be explained more fully below.

Braking means are provided for the roller 50 and, as shown in the drawings, these means may include the pair of brake shoes 63 adapted tov bear against the inner surface of the roller. As shown best in Figure 3, the brake shoes 63, which. are provided with a suitable resilient lining 64, are. each pivotally connected at one end. to. a bracket member 65 carried on the shaft 51. The shoes are hydraulically. operated by means of the power cylinder assembly 66 which is pivotally connected to, the upper end of each of the shoes 63, hydraulic fluid supply and return lines 67 extending through the hollow shaft 51. Coil spring 68: extends between. the upper ends of the shoes 63 and. normally tends to. urge the shoes inwardly and out of engagement with the walls of the roller 50-.

The operation of the device is as follows: With the mold 17 placed in the operative position shown, the compacting roller 50 is lowered by means of the power cylinder assembly 58 to the operative position wherein the distance between the roller and the inner surface of the mold is approximately equal to. the desired wall thickness of the finished pipe 70. The power source 13 is energized to spin the mold and wet concrete is delivered, into the mold in a manner well known. in the art. The vibrators. 40 are then actuated and the mold spun at a relatively high rate of speed to. form the pipe through the centrifugal forces thus set up.

During the spinning operation the brake shoes 63 are in the inoperative position out of contact with the walls of the roller 50, which is thus free to rotate through contact with the spinning concrete. The power cylinder assembly 58: is. operated to force the roller against the con crete to firmly compact the same. As shown in Figure 5,

with each revolution of the roller the lands 6 1 are forced, into the wet concrete, causing the larger aggregate particles to become embedded under the surface and simultaneously bringing to the surface the fine sand and mortar. Continued rotation results in complete coverage of the concrete surface by the lands, thus submerging substantially all of the more coarse aggregate particles and presenting a surface free of rough, protruding portions.

The inner wall or surface of the pipe thus formed, while free from roughness due to coarse aggregate particles, may carry the marks of the lands and: grooves. of the compacting roller 50. These marks, in the form of grooves or undulations, extend longitudinally of the pipe and, thus, are not especially detrimental to the efficacy of the finished pipe. However, for some purposes it is desir: able to produce a casting or pipe having an extremely smooth inner wall. This may be accomplished by troweling the concrete after the spinning and compacting operation described above has been carried out. The speed of the trunnion rollers, 12 is reduced to. lower the speed of rotation of the mold- 17 and, the power cylinder assembly 66 is actuated to stop the roller 50. with one of the smooth surfaces 62 in contact with the concrete. Pressure on the roller is released and the roller is allowed to. bear against the concrete with only its, own weight. The stationary surface 62 acts as a trowel in smoothing the surface of the concrete as it is rotated with the mold. It has been found that this troweling operation need be carried out for only about one minute to produce a smooth, cylindrical inner wall on the pipe.

A modified form of the, invention is illustrated in Figures 6 and 7.- and comprises a compacting roller generally indicated 80. This roller is also tubular in shape and is mounted forfree rotation in the manner described above, but differs from the roller- 50. in that it is proidfid. with. helical. or sp ra g o e e oqve preferably are spaced to provide lands 82 and are formed in two helical groups spaced by a pair of helical surfaces 83.

It has been found that with the use of the roller the larger aggregate particles are submerged under the concrete surface by the action of the grooves and lands, much in the same manner described above, but here the inner surface of the pipe is more easily troweled to provide an exceptionally smooth surface. This troweling may be accomplished by the use of a roller (not shown) having a smooth exterior surface, or the roller 80 may be used. In using the roller 80 for smoothing or troweling the pipe surface, the pressure on the roller is released so that only the. lands 82 and the surfaces 83 touch the inner surface of the pipe. The mold is then spun slowly in the manner described above until a smooth surface is obtained.

In operating the spiral; grooved roller 80, it has beenfound; that in some cases, the spiral grooves tend to.

force the fine aggregate particles toward one end of the pipe. The roller is provided for use in the event that; an undue amount of fines are thus distributed. This roller is similar to the roller 80, having the same right-hand helical grooves 81a spaced by lands 82a, but here a second pair of helical groups of left-hand grooves 91 of the same pitch as the grooves 81a are provided. Arcuate surfaces 92 space the respective pairs of helical groups of grooves 81a and 91. The operation of the machine with the roller 90 is the same as that described, when using the roller 80, but here, by reason of the right-. and left-hand grooves, any tendency for uneven distribution, of fines is eliminated.

Another modified form ofroller which has been found to be highly effective is; generally indicated in Figure 10. This, roller is provided with a single helical groove 101 and is equally as effective as the roller 80, although somewhat easier to manufacture.

In operating the roller 50, it has been found that where the circumference of the inner wall of the concrete pipe bears a certain relation to the circumference of h roller 50, or where there is a certain amount of slippage between the roller and pipe surfaces, the lands 61 on opposite sides, of the roller tend to contact the same areas of the pipe surface with each revolution of the pipe, resulting in incomplete coverage of the entire surface. Accordingly, the modified form of roller 50a illustrated in Figure 11 is provided for use in the event that such tendencies are exhibited by the roller 50. The roller 50a is similar to the roller 50, being provided with longitudinal grooves 60 and 60b spaced by smooth arcuate surfaces 6211, but here the lands 61a between the grooves 60a are diametrically staggered with respect; to the lands 61b between the grooves 60b. That is, the grooves 60a are each diametrically opposed to a land 61b, and likewise, the grooves 6012 are each diametrically opposed to a land 61a. Any tendency for the lands 61ato contact the same areas of the pipe wall which are contacted by the lands 61b is thus eliminated.

While there has been described what is at present considered preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various changes and modifications can be made therein without departing from the essence of the invention and it is intended to cover herein all such changes and modifications as come within the true. spirit and scope of the appended claims.

We claim:

1. A compacting roller for use in a centrifugal concrete casting machine, comprising an elongated body having a generally cylindrical surface, said surface having a pair of groups of longitudinal grooves defining therebetween a pair of smooth arcuate surfaces forming troweling areas.

2- In c mbination with a centrifugal concrete casting machine of the type having roller trunnions and a cylindrical mold rotatably carried on said trunnions, a cornpacting roller mounted for free rotation within said mold, said roller being provided with raised portions on the surface thereof for contacting freshly poured concrete on the interior of the mold to embed coarse aggregate particles under the surface of the concrete, said roller being further provided with longitudinal arcuate surfaces, and braking means for said roller whereby rotation of the roller may be stopped for use of said arcuate surfaces in troweling the concrete.

3. A compacting roller for use in a centrifugal concrete casting machine, comprising an elongated body having a generally cylindrical surface, said surface having a pair of groups of longitudinal grooves therein, lands between each groove, and a pair of smooth arcuate surfaces forming troweling areas between each of said pair of groups of grooves, the grooves of each pair being spaced so that each groove is diametrically opposed to a land.

4. In combination with a centrifugal concrete casting machine of the type having roller trunnions and a cylindrical mold rotatably carried on said trunnions, a compacting roller mounted for free rotation within said mold, said roller comprising a body having a generally cylindrical surface, said surface being provided with a plurality of spaced grooves therein, said grooves extending lengthwise of the body and defining therebetween raised portions for contacting freshly poured concrete on the interior of the mold to embed coarse aggregate particles under the surface of the concrete, and braking means for said roller whereby rotation of the roller may be stopped for use of said raised portions in troweling the concrete.

References Cited in the file of this patent UNITED STATES PATENTS 1,750,748 Edmunds Mar. 18, 1930 2,275,535 Magnani Mar. 10, 1942 2,285,497 Cuno June 9, 1942 2,375,276 Brown May 8, 1945 FOREIGN PATENTS 118,079 Australia Jan. 27, 1944 423,842 Italy L July 30, 1947 

